Improvement in turn-tables for swing-bridges



GEORGE wALTEHs.

Improvement in Turn-Table for Swing-Bridges..l

No.124,400. l 'Patented Mar-055,187.2.

f UNITED STATES PATENT OFFICE.

GEORGE WALTERS, OF PHCENIXVILLE, PENNSYLVANIA, ASSIGNOR TO PHCENIX IRON COMPANY,77 OF SAME PLACE.

IMPRVEMENT IN TURN-TABLES FOR SWING-BRIDGES.

Specification forming part of Letters Patent No. 124,400, dated March 5, 1872..

SPECIFICATION.

I, GEORGE WALTERS, of Phoenixville, in the county of Chester, State of Pennsylvania, have invented an Improved Turn-Table for Swing-Bridges, Snc., of which the following is a specification:

Nature and Object of the Invention.

My invention consists of a turn-table too fully explained hereafter to need preliminary description, the construction of the table being such as to secure strength, rigidity, and ready adjustment of the parts without excessive weight.

Description of the Accompanying Drawing.

Figure 1 is avertical section of a turn-table with my improvements 5 and Fig. 2, a plan view of the same.

General Description.

The turn-table proper consists of what may be termed a circular girder, A, composed, in the present instance, of an upper ring, a, and lower ring, b, the two rings being connected together by an outer casing, e, and inner easing, el, of plate iron, properly strengthened at intervals by suitable T-ribs; and the turn-tablerests (not with its full Weight, however, as explained hereafter,) on rollers d d, which bear on a circular track, ff, secured to a pier or foundation, B. D is a central pivot-stand, of cast-iron, firmly secured to the pier, and on this stand, near the base of the same, a ring, E, is arranged to turn freely, rods F, near the outer ends of which are the rollers d, being secured at their ends to said ring, the extreme outer ends of all the rods being connected together by a ring, n. An annular plate, G, is also arranged to turn freely on the pivot-stand, and from the edge of this plate to the lower ring b of the circular girder A radiate an appropriate number of horizontal stays, H, which I prefer to make of wrought-iron tubes, and which are provided at one or both ends with proper means of longitudinal adjustment. In the present instance this adjustment is accomplished by set-screws, with one of which the solid outer end of each bar is provided, the outer end of each screw fitting into a socket on the ring b, so that each staymay be lengthened or shortened lat pleasure by simply turning its screw. The annular plate G is connected to and suspended froma disk, K, (referred to hereafter,) by any appropriate nnmber of bolts, t' z'. I is the pivot-head, and J is the pivot, (which I prefer to make of steel,) the pivot so iittin g in a recess in the central stand D as to turn freely as well as to have alimited lateral vibration therein, concave disks (which I prefer to make of steel,) being placed in the recess of the block as bearings for the pivot. Kis a substantial cast-iron disk, through which pass bolts m m, the threads of which are adapted to those of nuts n n, sunk or partly sunk into the under side of the said disk, the steel-pointed lower ends of the bolts entering recesses in the pivot-head I, and these recesses having concave steel washers for the bolts to bear on. A series of horizontal adjustable stays, E', precisely similarito the stays H below, radiate from the disk K to the upper ring a of the circular girder A, and a number of diagonal tension-bars, M, pass at one end through thel flange of the disk K, and, at the opposite end, through the lower ring b of the circular girder A, the rods being furnished at both points with suitable nuts. N N is a transverse girder, made in two parts, as shown, each part extending from the inside of the circula-r girder to which it is secured to the edge of the disk K, beyond which point the lower edge of each portion projects so as to receive the bolts p, by which it is suspended from the disk K. The swing-bridge rests on the turntable I have described, the lower chords or beams of the bridge (shown by dotted lines in Fig. 1,) resting on the upper edge of the circular girder, and on the transverse girders. It is most -important that a swing-bridge should admit of bein-g turned quickly and by as little exertion as possible, and this couldnot be done if the weight of the bridge and turn-table, or any great portion of that weight, was supported on the rollers d. In fact the rollers should have very little more duty to perform than that'ot steadying the turn-table and lpreventing an undue vibration ofthe same, the main weight being supported at the central pivot J by the pivot-stand D. Presuming that in erecting the turn-table and its bridge, in the first instance, care has been taken in adjusting the horizontal stays and tension-bars to relieve the rollers d from the Weight of the bridge, so that they may have none but their legitimate steadying duty to perform-that of thelateral steadyin g of the tablethe latter will, in time, owing to the constant travel of heavy trains, be liable to sag and bear with suoliY a Weight on the rollers as to render the turning ofthe bridge a very difficult matter. When this occurs, all that is necessary is to turn the bolts m so as to slightly elevate the disk K, and this, through the diagonal tension-rods, will necessarily elevate the outer edge of the circular girder A, and thus relieve the rollers d from undue Weight. If on the contrary the table has too much lateral play or vibration, a slight turn of the bolts m m will lowerthe disk K, and, consequently, depress the circular girder and cause just as much of its Weight a-nd that of the superincumbent bridge to bear on the rollers as to insure proper steadiness. It will be observed in Fig. 1 that these bolts m are carried upward nearly to the iioor of the bridge, which is shown by dotted lines, so that they be accessible to a suitable screw-key. The adjustment of the turntable, however, is not dependent on the bolts m m, for it will be readily seen that the adjustment of the table, as it regards its bean ingon the rollers d, can be accomplished by the adjustment ofthe longitudinal rods Il and H and diagonal tension-rods M in a manner which will be readily understood Without eX- planation; and this Inode of adjustment may i2 moo but in most cases the bolts m o will sutlice to bring about the desired result.

I have vreferred to my improved turn-table as bein gused in connection with swin g-brid ges, and it is especially Well adapted for this use; but it can be employed with advantage on rail` roads and in other localities Where an easy moving and substantial turn-table is required.

Although I have illustrated and described a peculiar manner of constructing the central portion of the turntable, Which portion is fully set forth and claimed in a separate application for a patent, my present applica-tion does not refer to any specic inode of constructing the said central portion, inasmuch as the tensionrods M and stays H and Il may be employed ior connecting the annular girder to any cen tral hub or vane of a turn-table.

Claims.

1. The annular girder A connected to the central hub or vane of a turn-table by stays H and adjustable diagonal tension-rods M, substantially as described.

2. The combination of the above With the stays H.

In testimony whereof I have signed my name to this specification in the presence of two subscribin g witnesses.

GEORGE VVALTERS.

Vitnesses:

J No. B. HARDING, HARRY SMITH. 

